Straight-line guide for the handles of compasses



A. RENZELBERG. STRAIGHT LINE GUIDE FOR THE HANDLES 0F COMPASSES.

APPLICATION FILED OCT-15,192].

Patented Aug. 8, 1922.

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in uremia?) AUGUST RENZELBEBG, NUREMBERG,.GERMA1IY, ASSIGNOR TO THE FIRM REISSZEUGFABRIK EICHIVIULLER 8t (10., 0F NUREMBERG, GERMANY.

STRAIGHT-LINE GUIDE FOR THE HANDLES OF COMPASSES.

Specification of Letters Eatent.

Patented Aug. 8, 1%22.

Application filed October 15,1921. Serial No. 508,047.

To all to hem it may concern:

Be it known that I, AUcUsr Rmvznnnnno, a citizen of the German Republic, and a resident of Nuremberg, Germany, have invented a new and useful Improved Straight-Line Guide for the Handles of Compasses, of which the following is a specification.

Straight-line guides for the handles of compasses, in which on opening the compasses the handle adjusts itself by friction into the middle line of the gap of the compasses are known. The invention consists in constructing the friction body as a rotary pin which is situated in the handle of the compasses. The thus improved straight-line guide is illustrated, by way of example, in the accompanying drawing, in which similar letters of reference denote similar parts throughout the several views, and in which Figure 1 is a front view of about the upper half of compasses constructed according to this invention, the uppermost portion, i. e. the handle, being shown in longitudinal section. Figure 2 is a side view of the parts shown in Fig. 1. Figure 8 is an illustration similar to Fig. 1 and shows a slightly modified form of construction. Figure 4 is a side view of the parts shown in Fig. 3.

The heads 4 and l of the legs of the com passes lie side by side in a known manner in the yoke 1. Upon the heads i, a presses from above a rotary pin 2 which, preferably, is thickened at its lower end so as to form or to have a foot and I prefer to provide this foot with a central cavity turning it into a circular inverted trough which contacts only at its rim with the two heads 4;, 4.

The pin 2 is loosely rotatable in the hollow handle which forms an extension of the yoke 1. In order to obtain the necessary or suflicient contact and friction between the pin 2 and the heads 4-, a, a pressure screw 3 is inserted into the top of the handle, the lower or inner end of this screw bearing and pressing upon the upper end of the rotary pin.

On opening the compasses, the pin 2 is rotated (by the mediation of its foot, as described and shown) by means of the moved head (4L or a), and while being rotated the foot rolls along upon a corresponding portion of the circumference of the other head (4 or 4;). Owing to the two heads (4: and l) moving relatively to one another, it is immaterial which of them is held fast and which ismoved, or whether both legs are drawn apart simultaneously; the motion of the pin foot relatively to the head l is equal to its motion relatively to the head 1, so that it adjusts itself automatically into the mid dle line relatively to the legs of the compasses.

As the rotary pin although being positively moved, is not constrainedly moved, it may occasionally get a little out of the proper middle line. To correct such a deviation I have devised two means, of which the one is shown in'Figs. 1 and Q, the other in Figs. 3 and 4. In the first instance the yoke 1 is downwardly elongated to below the heads 4 and 4, and the two legs of the yoke are connected with each other by pin or bolt 5, the shank of which lies in oppositely located cavities of the legs if the compasses are closed, as in Fig. 1. Supposing, the handle (inclusive, of course, the rotary pin) has got out of the proper middle line, it is automatically turned back into its proper posi tion by the operator closing the compasses, when the legs will grasp the pin 5 between them and readjust the handle.

In the form of construction shown in Figs. at and 5, the yoke 1 is not elongated, and there is, consequently, no such pin or bolt like 5 (Figs. 1 and 2) but each of the heads 4 and 4 has a pin 6, which in the closed position of the compasses contacts with one of the yoke legs. The distance between the axes of the two pins 6 corresponds to the breadth of a yoke leg, and it is obvious that if the handle should have left its proper middle position relatively to the legs of the compasses, this latter need merely. be closed when the handle will be automatically readjusted.

Having thus particularly described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A straight-line guide for the handle of compasses, comprising, in combination, diskshaped heads forming the rotatory ends of the legs of the compasses; a yoke forming the bearing for said heads; a hollow handle forming an elongation of said yoke and a rotary pin in said handle; the lower end of said pin being in frictional contact with said two disk-shaped heads at their circumference, for the purpose set forth.

2. A straightdine guide for the handle of compasses, comprising, in combination, diskshaped heads forming the rotatory ends of the legs'of the compasses;-a yoke forming the bearing for said heads a hollow-handle forming an elongation of said yoke; a rotary pin in said handle; and a frictional contact member forming the lower end of said pin and being in frictional contact with said two disk-shaped heads at their circumference, for the purpose set forth.

3. A straight-line'g-uide for the handle of compasses, comprising, in combination, diskshapedheads forming the rotatory ends of thelegs of the-compasses; a yokeforming the bearingfor said heads; a hollow handle forming an elongation of saidyoke; a rotary pin in said handle and a pressure screw also located in the said handle co-axially with saidp-in, for the purpose set forth.

4.'A straight-line guide for the handle of compasses, comprising, in combinatiomdiskshaped heads forming the rotatory ends of t-he legs of the compasses; a yoke-forming the bearing forsaid heads ;"-a hollow handle forming an elongation of said yoke; a rotary pin in said handle and a "frictional contact member forming the lower end of said pin I andbeing in frictional contact with saidtwo AUGUST RENZELBERG.

Witnesses:

HEINRICH FIETH, I GEoRo LEITNER. 

